Recurrent orbital schwannomas: clinical course and histopathologic correlation

Plexiform Schwannoma of the Eyelid

Plexiform schwannoma of the lacrimal gland of the palpebral lobe has not been previously described. This 41-year-old male presented with a 2-year history of a left upper eyelid mass and associated regional irritation. MRI of the head and orbits confirmed a left superolateral multinodular mass centered on the palpebral lobe of the left lacrimal gland. Excision revealed a schwannoma of the plexiform subtype.

Conservative or surgical management of orbital schwannomas: a population-based case series

INTRODUCTION

Orbital schwannomas (OS) are rare occurrences with no more than 500 cases reported in the literature. The tumor's potential to compromise the delicate neuro-ophthalmic structures within the orbit prompts surgical removal. Tumor removal is performed by ophthalmologists, often requiring a multidisciplinary surgical approach. The literature contains a very limited number of cases managed non-surgically. However, the inherent risks of orbital surgery warrant a comparison of the outcomes of conservative and surgical management strategies.

AIMS

To review the national Swedish experience with the management of orbital schwannomas.

METHODS

The study center is the primary Swedish referral center for the multidisciplinary management of orbital tumors, including schwannomas. During the period of 2005 to 2021, 16 patients with an OS diagnosis were managed at the center.

RESULTS

Four patients initially underwent surgery where gross total resection (GTR) was achieved in three (75%) and subtotal resection (STR) in one (25%) case. The remaining 12 patients, who had a low risk of neuro-ophthalmic impairment, were managed conservatively with radiological and clinical examinations at regular intervals. After an average follow-up of 17 months, surgery was performed in three of these cases (25%). No recurrences or tumor growths were detected on radiological follow-ups (mean 50 months), and all patients experienced postoperative improvement at clinical follow-up (mean 65 months). The remainder of the conservatively treated patients (n=9) experienced no clinical progression (mean 30 months). A slight radiological tumor progression was detected in one patient after 17 months.

CONCLUSION

There were no differences in long-term outcome between patients who had been managed with early surgery and those operated later after an initially conservative management. Conservatively treated patients had minimal to no symptoms and remained clinically stable throughout the follow-up period. Based on these findings, conservative management may successfully be adopted in cases with mild symptoms, no signs of compressive optic neuropathy and low risk of neuro-ophthalmic impairment. Conversion to surgical management is indicated upon clinical deterioration or tumor growth. Based on the findings of this study a decision tree for the management of orbital schwannomas is suggested.

Diffusion-weighted imaging of the orbit

Orbital lesions compose a heterogeneous group of pathologies that often present with non-specific imaging findings on conventional magnetic resonance imaging (MRI) sequences (T1-and T2-weighted). Accordingly, the application of diffusion MRI offers an opportunity to further distinguish between lesions along this spectrum. Diffusion-weighted imaging (DWI) represents the simplest and most frequent clinically utilised diffusion imaging technique. Recent advances in DWI techniques have extended its application to the evaluation of a wider spectrum of neurological pathology, including orbital lesions. This review details the manifestations of select orbital pathology on DWI and underscores specific situations where diffusion imaging allows for increased diagnostic sensitivity compared to more conventional MRI techniques. These examples also describe preferred management for orbital lesions identified by DWI.

Orbito-cranial schwannoma-a multicentre experience

OBJECTIVES

To describe the features, management approaches, and outcomes of orbito-cranial schwannomas.

METHODS

Retrospective review of ten patients with orbito-cranial schwannomas managed in six orbital services over 22 years. Data collected included demographics, presenting features, neuroimaging characteristics, histology, management approach, complications, and outcomes.

RESULTS

Mean age of the patients was 41.4 ± 19.9 years, and 6 (60%) were females. The majority presented with proptosis (90%), limited extraocular motility (80%), eyelid swelling (60%), and optic neuropathy (60%). Most lesions (80%) involved the entire anterior-posterior span of the orbit, with both intra- and extraconal involvement. All tumours involved the orbital apex, the superior orbital fissure, and extended at least to the cavernous sinus. Surgical resection was performed for all. Seven (70%) of the tumours were completely or subtotally resected combining an intracapsular approach by an orbital-neurosurgical collaboration, with no recurrence on postoperative follow-up (6-186 months). Three underwent tumour debulking. Of these, two remained stable on follow-up (6-34 months) and one showed progression of the residual tumour over 9 years (cellular schwannoma on histology) necessitating stereotactic radiotherapy (SRT) for local control. Adjuncts to the orbito-cranial resection included perioperative frozen section (n = 5), endoscopic transorbital approach (n = 2), and image-guided navigation (n = 1). Post-surgical adjuvant SRT was used in three subjects.

CONCLUSIONS

These results highlight the possibility of successful surgical control in complex orbito-cranial schwannomas. A combined neurosurgical/orbital approach with consideration of an intracapsular resection is recommended. Recurrence may not occur with subtotal excision and observation may be reasonable. Adjunctive SRT for progression or residual tumour can be considered.

Orbital schwannoma management: a case report, literature review, and potential paradigm shift

PURPOSE

To present a case of orbital schwannoma and assess the literature on treatment modalities.

METHODS

A MEDLINE literature search for cases of orbital schwannomas was performed using the PubMed search tool using the search terms "orbital schwannoma" and "orbital neurilemmoma." Papers were included if they were peer-reviewed, published in English, discussed management, and included the search terms. Each article was rated using the scale developed by the British Centre for Evidence-Based Medicine. In addition, we present a case report of an orbital schwannoma.

RESULTS

A total of 428 articles were found. 102 met the criteria for inclusion. Only two articles met Level 1 evidence and 16 were important to the clinical care process. We report a case of a biopsy-proven orbital schwannoma managed conservatively with observation over a 4-year period due to risk of cosmetic disfigurement with tumor removal. There has been no change in tumor size and no associated complications during follow up.

CONCLUSIONS

There is a paucity of data on the natural history of orbital schwannomas. Based on our review of the literature, we recommend observation for asymptomatic or minimally symptomatic orbital schwannomas with minimal growth over an extended period of time. For rapidly growing tumors or large tumors affecting key structures causing visual loss, diplopia, aesthetic disfigurement, or patient discomfort, a more aggressive approach may be necessary.

Orbital schwannoma with calcification treated by intracapsular excision: A case report

RATIONALE

Orbital schwannoma is a relatively rare orbital tumor, and calcification of the lesion is rarely found in the orbit. We report a case of orbital schwannoma which was characterized by calcification in the orbital muscle cone, and was cured by intracapsular excision.

PATIENT CONCERNS

A 54-year-old female with a complaint of a mass in the left orbit during a magnetic resonance imaging examination and symptom of dizziness 6 months before, presented with painless exophthalmos and vision decline in the left eye.

DIAGNOSES

According to clinical manifestations, imaging examinations and postoperative immunohistochemical examinations, the diagnosis was orbital schwannoma, with calcification in the muscle cone.

INTERVENTIONS

The patient was treated by intracapsular excision of the left orbit. We removed the intracapsular mass and most part of the cyst wall in order to prevent orbital apex syndrome.

OUTCOMES

The diagnosis of schwannoma with calcification was confirmed finally through histological and immunohistochemical exam. The patient was followed up for 28 months and the orbital CT scan showed that there were no significant lesions found in the orbital muscle cone.

LESSONS

Understanding clinical, imaging diagnostic, and histopathological features of rare orbital schwannoma with calcification will facilitate timely diagnosis and treatment of this condition. The intracapsular excision can help in avoiding complications.

Diagnosis of plexiform schwannoma of the foot in a 66-year-old male: a case report and literature review

Plexiform schwannoma is a rare tumor in the lower extremity which grows slowly and is noninvasive. The tumor size is usually less than 2 cm. The main affected population of this disease is concentrated on the age group of 20 to 50 years old. In this study, we reported a rare case of 66-year-old male with a large soft tissue mass on his right foot with a tumor size larger than 7 cm. The ultrasound was performed and showed circumscribed hypoechoic image, indicating a suspected diagnosis of lipoma. The subsequent MRI showed a multilobulated heterogenous signal on T2WI and STIR sequence with mild enhancement, suggesting hemangiomas. Then the tumor of the patient was removed for pathological examination and the results confirmed the diagnosis of plexiform schwannoma. Patient recovered well and had no recurrence in 9 months after the surgery. CT, MRI, and ultrasound are useful to distinguish these rare tumors from other soft tissue lesions, in contrast, MRI has higher sensitivity and provides more accurate diagnostic information. This case report provides a deep understanding of plexiform schwannoma. In the diagnosis of large soft tissue tumors in the lower extremity of the elderly, attention should be paid to the differential diagnosis of plexiform schwannoma to improve the diagnosis level.

Orbital Schwannoma

Orbital schwannomas are rare neoplasms of the orbit. The presenting symptoms are often nonspecific. Classic imaging characteristics seen on magnetic resonance imaging (MRI) and orbital ultrasound can be useful to help aid in the diagnosis of orbital schwannoma. When diagnosed, the goal of treatment is complete surgical excision. The location of the tumor within the orbit dictates which surgical approach would provide the best exposure. When complete excision is achieved, recurrence rates are very low. This article addresses the etiology, patient population, presentation, natural history, and differential diagnosis of orbital schwannomas. Imaging characteristics and histopathologic subtypes are reviewed. Treatment goals, approaches, and specialties involved in the management of these patients is discussed. Finally, a representative case is presented.

Primary recurrent orbital schwannoma treated with surgical excision and Mitomycin-C

Purpose

Primary orbital schwannoma (POS) is a slow growing, benign encapsulated peripheral nerve sheath tumor that occurs infrequently within the orbit. Recurrence of POS is extremely rare. Previous speculations for reasons of recurrence include incomplete excision and tumor seeding.

Observations

We present the fifth case reported in the literature to date of POS that had 2 episodes of recurrences within 8 years after diagnosis, in which rapid and insidious relapses were observed after initial surgical resection. This is also the first reported recurrent POS in which topical Mitomycin-C (MMC) has been employed during surgical excision with an aim to prevent further recurrences.

Conclusions

AND IMPORTANCE: Whilst complete surgical excision remained the standard for management for most POS, when there are multiple recurrences and in cases where total excision is not possible, addition of topical MMC may be an option that may bring about tumour regression as demonstrated in our case.

Multiple heterogeneous tumors in orbit: a case report

Primary orbital tumors are common; clinically common are single tumors in orbit; and cavernous hemangioma is the most common. Multiple tumors in the same orbit are rare, which have homology and heterogeneity. Multiple tumors of homology are multiple textures of a tumor while multiple heterogeneous tumors have two or more textures. Various tumor tissues, heterogeneous multiple orbital tumors are sporadic. Our department admitted one patient in October 2015. A 54-year-old male patient had proptosis growing gradually in his right eye beginning ten years ago, with decreased vision for more than one year. The primary diagnosis of the right eye orbital double-source primary tumor was diagnosed by imaging. The pathological examination after the operation was confirmed as cavernous hemangioma and schwannomas.

Imaging characteristics and surgical management of orbital neurilemmomas

AIM

To review imaging characteristics and surgical outcomes of orbital neurilemmoma.

METHODS

Retrospective review of 21 patients with orbital neurilemmoma managed at the Zhongshan Ophthalmic Center of Sun Yat-sen University from June 2005 to December 2016. All patients underwent surgical excision following preoperative imaging including ultrasonography, computed tomography (CT) and magnetic resonance imaging (MRI).

RESULTS

Among these patients, 11 were male and 10 were female, with age ranging from 12 to 75y (average, 40.3y). Ultrasound of the orbit showed a roundish well-demarcated orbital mass with low or middle internal reflectivity in each case. Dark inner liquid fields were detected in 28.6% of these cases. Doppler ultrasound demonstrated blood flow signals in these masses. CT showed that the tumors were either homogeneous or heterogeneous. MRI of T1WI revealed isointense or hypointense tumors, while the T2WI indicated heterogeneous hyperintense lesions. Gd contrast MRI demonstrated heterogenous or homogeneous enhancement initiating from the wide area of the lesion. Six patients underwent lateral orbitotomy and 15 anterior orbitotomy. All tumors were completely removed. After a mean follow-up of 1.8y, 3 patients experienced reduced vision while the remaining 10 patients showed improved vision after surgery. One patient experienced a mild limitation of upward motility. No recurrence occurred.

CONCLUSION

Orbital neurilemmoma is a relatively rare, benign orbital tumor. Effective diagnosis requires a combination of ultrasonography, CT and/or MRI. These imaging techniques are also vital to differentiate neurilemmomas from other orbital masses like that of cavernous hemangiomas and meningiomas. Successful treatment requires complete resection of the neurilemmomas as performed either by lateral or anterior orbitotomy. Recurrence is rare after complete removal.

Orbital Schwannoma: Radiographic and Histopathologic Correlation in 15 Cases

PURPOSE

To evaluate the relationship between radiographic and histopathologic features of orbital schwannoma.

METHODS

Retrospective review of 15 patients with orbital schwannoma managed at an ocular oncology service.

RESULTS

The mean patient age at the time of presentation was 42 years old (median 40, range 15-64 years). The orbital schwannoma was found incidentally (n = 2) or with symptoms of proptosis (n = 2), blurred vision (n = 3), pain (n = 3), eyelid swelling (n = 2), diplopia (n = 2), or headache (n = 1). The mean duration of symptoms was 15 months (median, 9; range 1-60 months). The tumor occupied the superior (n = 11) or inferior (n = 4) orbit. Antero-posterior tumor location involved the anterior (n = 2), middle (n = 3), posterior (n = 4), or entire (n = 6) orbit. MRI was performed in 12 patients (80%) and CT was the only form of imaging in 3 patients (20%). The T1-weighted MRI (n = 11) showed the mass as isointense (n = 10) or hyperintense (n = 1) to the extraocular muscles). On T2-weighted MRI (n = 10), the mass demonstrated hyperintensity (n = 9) or hypointensity (n = 1). Histopathologic assessment demonstrated Antoni A (n = 12) and Antoni B (n = 12) patterns. Antoni A pattern correlated with hyperintensity on T1-weighted MRI and hypointensity on T2-weighted MRI. Antoni B pattern correlated with hypointensity on T1-weighted MRI and hyperintensity on T2-weighted MRI. As Antoni B approached >50% of the solid mass (n = 8), both T1- and T2-weighted MRI images were more likely to be heterogeneous (n = 7, 88% and n = 6, 75%, respectively).

CONCLUSION

Orbital schwannomas are nearly always benign, well-encapsulated slowly progressive tumors. Due to the biphasic distribution of Antoni A and Antoni B pattern, the appearance on MRI has a variable degree of heterogeneity. Antoni A pattern correlated with hyperintensity and Antoni B pattern correlated with hypointensity on T1-weighted MRI.

Clinicopathological features of peripheral nerve sheath tumors involving the eye and ocular adnexa

Peripheral nerve sheath tumors (PNSTs) are known to occur in the orbit and comprise 4% of all orbital tumors, but have not been well studied in contemporary literature. Ninety specimens involving the eye and ocular adnexa (1979-2015) from 67 patients were studied. The mean age was 32.5years. Locations included orbit (58.9%), eyelid (60.0%), and other ocular adnexa. Most specimens were neurofibromas (70.0%), followed by schwannomas (11.1%), neuromas (11.1%), granular cell tumors (n=4), nerve sheath myxomas (n=2), and malignant PNST (n=1). Fifty-six (88.9%) neurofibroma cases were neurofibromatosis 1 associated. Among neurofibromas, 31.7% were localized, 38.1% were plexiform, 25.4% were diffuse, and 4.8% were diffuse and plexiform. These tumors involved skin (31.7%), soft tissue (11.1%), skeletal muscle (22.2%), peripheral nerve (63.0%), lacrimal gland (20.6%), and choroid (n=1). Other histologic findings included pseudo-Meissner corpuscles (27%), Schwann cell nodules (4.8%), prominent myxoid component (7.9%), melanin-like pigment (3.2%), and inflammation (14.3%). Available immunostains included S100 (+ in 15/15 cases), EMA (+ in 2/4 cases), CD34 (+ in 4/4 cases), and Ki-67 (<1% in 4/4 cases). Among 10 schwannomas, 8 were conventional and 2 were plexiform. Observed features included capsule (n=5), hyalinized vessels (n=5), Verocay bodies (n=7), and Antoni B pattern (n=5). Immunostaining included S100+ in 4 of 4 cases, and collagen IV+ and Ki-67 <1% in 3 of 3 cases. Neurofibromas are the most common PNST involving the eye and ocular adnexa, and the majority are associated with neurofibromatosis 1. Plexiform and diffuse patterns and the presence of pseudo-Meissner corpuscles are relatively frequent in this area.

Plexiform schwannoma involving the trachea and recurrent laryngeal nerve: a case report

Plexiform schwannoma is an infrequent variant of schwannoma characterized grossly and microscopically by multi-nodular growth. Although plexiform schwannoma has such growth patterns, it is a benign tumor as well as a conventional schwannoma. It rarely infiltrates adjacent organs or arises from the organ itself. In this report, we describe a case in which plexiform schwannoma involved the tracheal wall and left recurrent laryngeal nerve to a great extent. As it was expected to be difficult to achieve complete resection even if the longer tracheal resection were performed, we preserved the trachea and resected as much of the tumor as possible. This report is thought to be the first to describe plexiform schwannoma infiltrating or growing from the trachea. Although the treatment decisions we made might be controversial, we believed we could make an accurate diagnosis and adequate treatment decision through surgery.

Proliferation and arrest: the genetics of orbital disorders

PURPOSE OF REVIEW

Oculoplastic genetic diseases can be divided into eyelid, lacrimal, and orbital disorders. The purpose of this review is to develop a rational approach to the categorization of genetic diseases that affect the orbit and review the most recent developments.

RECENT FINDINGS

Genetic disorders that affect the orbit can simply be divided into whether they cause proliferation or arrest of orbital structures. Proliferative conditions include vascular, neural, bony, mesenchymal, and lymphoid. Conditions that cause arrest can be subcategorized into whether they cause soft tissue or bony arrest of development. The genetics of many of these conditions have been elucidated and novel treatments, based on the molecular defects, have been utilized with some success.

SUMMARY

Molecular advances may result in substitution of a molecular categorization scheme for the one proposed in this manuscript. Delineation of the underlying molecular causes of these disorders will result in earlier, less invasive procedures than those that are currently employed.

Orbital schwannomatosis in the absence of neurofibromatosis

PURPOSE

The aim of this study was to describe 3 cases of primary orbital schwannomatosis without associated systemic neurofibromatosis.

METHODS

This is a retrospective interventional study of 3 patients who presented with multiple, distinct masses in the orbit (n = 3) as well as in the hemiface (n = 1). The clinical presentation, imaging features, surgical procedures, and outcomes were defined.

RESULTS

Two women and a man presented with of exophthalmos and diplopia. Pain was the most prominent complaint in 2 patients. None of the patients had associated systemic neurofibromatosis by history or examination. Radiologic evaluation with computed tomography or magnetic resonance imaging of orbit revealed multiple well-demarcated intraconal and extraconal masses. Masses were excised, and histopathology confirmed all masses to be schwannomas. Postoperative follow-up was uneventful with alleviation of primary complaints in all patients.

CONCLUSIONS

Multiple orbital schwannomas (primary orbital schwannomatosis) may be observed in patients without systemic association of neurofibromatosis. Management includes surgical excision of the tumors to achieve relief from their mass effects.

Case presentations and review of plexiform schwannoma in the foot

Plexiform schwannoma is a soft tissue tumor that rarely presents in the lower extremity. We have reported on 2 cases of plexiform schwannomas that occurred in the foot and ankle. Owing to the relative obscurity of this condition in the lower extremity, we have also provided an overview of plexiform schwannomas and discussed the differences between this and other suspicious nodular soft tissue masses. The first patient was a 38-year-old female, who had a soft tissue mass located on the lateral aspect of her right foot that became symptomatic. The second patient was an 11-year-old male, who had a symptomatic soft tissue mass on the plantar aspect of his right foot. Both patients underwent surgical excision of the tumor.